Lock



@am 2&3, E933. N. B. HURD 399329363 LOCK Filed May 20. 1933 INVENTOR Na/14A Hwa fel l A:

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ATTORNEYS Patented ct. 24, 1933 'rss Ultriumv STA f vLeases?.

LOCK

Norman B. Hurd, Newington, Conn., assignor to The American Hardware Corporation,

New

Britain, Conn., a corporation of Connecticut Application May 20, 1933. Serial No. 671,968 claims. l (ci. vil-i7) This invention relates to certain new and useful improvements in locks of the so-called pin tumbler type.

The main object of the invention is to provide 5 means to resist the unlawful operation of the lock by anyone skillful enough to succeed in picking the same so as to freeV the key .plug from its normal locked position.

In the accompanying drawing, I show my invention in a preferred form only, being aware that modifications may be made therein Withoutdeparture therefrom.

In the drawing Fig. 1 is a plan view of the complete structure;

Fig. 2 is mainlya longitudinal section thereof;

Figq is a cross-section on the line l3 4. of

Fig. 4 is a similar View showing certain parts in a different position.

1 represents the lock body or casing sometimes termed the cylinder. 2 represents the usual key plug rotatable in said body and provided with a keyway or slot 3 for a key 3. 4 4 are the usual tumbler elements in the plug, and 5 5 are the usual spring pressed tumbler elements in the body for locking the plug against rotation. If

anyone should be skillful enough to set the tumblers, without using a proper key, so as to release the plug, said'plug may be only partially turned v in either direction from that position since it will quickly encounter plug blocking means which will prevent the continued turning movement.

In locks of this type, the rear of the plug is usually provided with the `well known-roll-back 2 A or spindle connection, whereby movement of the plug may be transmitted to other well known locking or latching mechanism (not shown) for operating the latter. By the present invention if the 'plug is released by picking, it will be 40, checked before it can be turned far enough to operate said mechanism, the checking means being so constructed as to add to the diiculty of unlawful operation. This end I accomplish by the means about to be described. n

In the body 1, and out of line with the bores in which the tumblers 5 5 are located, I provide means which will automatically engage and block the plug after a partial turn by anything other than the proper key. I preferably provide such blocking means in the body 1 on opposite sides of the bores for the tumbler sections 5 5 so as to check turning movement of the plug in either direction unless a proper key is used. In the pary tumbler elements .5 5. This bore 6 intersects the wall of the bore in which the plug is located. The axis of the bore 6 is at a substantial angle to the radius of the plug, being preferably vabout tangential thereto. It is likewise in the plane of rotation of one of theA bores for the tumbler elements 4 in the plug so that when the latter has been turned to the position shown in Fig. 4, the end of this tumbler bore will intersect the end of the bore 6. '7 is a spring pressed plunger in bore 6, which, unless the tumbler element-4 is projectedv by a proper key as shown in Fig. 3, will be projectedinto the end of the tumblerk bore, asshown in Fig.y 4, thus blocking the continued turning movement of the plug in a clock-v wise direction. If a key 3v is used, as indicated in Fig. 3, the end of the tumbler 4 will stand iiush with the circumference of the plug, and thus the plunger *7 willbe held back so that the plug 2 may be rotated freely. '7' represents the blocking tumbler on the opposite side of the line of bores for the locking tumblers 5, and since the same corresponds in construction and operation to the plunger 7, further description is unnecessary. It may be said that one or more of these blocking plungers 7 7 may be provided on one or both sides of the bores in the body for the locking tumblers 5.

While the blocking plungers '7 7'v resist the unlimited turning movement of the plug in either direction away from its normal locked position, unless operated by a propery key, it is obvious that if the position of the plug has been disturbed and is in fact engaged by either of the blocking tumblers, it may be turned back to its operative normal' locking position, since the blocking plungers will be repressed thereby; for example, if the plug should be moved to the position shown in Fig. 4 by a clockwise movement, a reverse or counterclockwise movement will re# press the blocking plunger 7. It will also be noted that, unless a proper key7 is used, one or the other of the plungers 7 7 may projectinto the back of the key slot and thus interfere with the turning of the plug. Whenever a proper key is inserted, however, the presence of the key in the keyway, and the projection of the plug tumbler element, or elements, will free the plug from any interference by either of the plungers 7 or 'l'.

From the foregoing, it is apparent that the present invention places a further obstacle in the way of anyone who would attempt to unlaw-v fully operate the lock after successfully picking the same to the extent of freeing the plug. from its normal locked position.'v

Inasmuch as the blocking means 7 7 cannot be reached by a picking tool, and inasmuch as an outward movement of the complementary tumbler elements 4 will cause the blocking plungers to bind in their respective bores, it is apparent that increased diiculty is put in the way of anyone who attempts to unlawfully operate the same.

While I am aware that this invention is susceptible of modifications, the form that I have shown and particularly described is one that will effectively accomplish the intended purpose.

I claim:

l. In a pin tumbler` lock, a body, a key plug rotatable therein, key controlled locking tumblers in said body and plug, a plug blocking means in said body on one side of the looking tumblers therein, means for projecting said blocking means into the end of a tumbler bore in the Yplug to block rotation of the latter in one direction, said blocking means being disengageable from its blocking position by a reverse rotation of said plug.

2. In a pin tumbler lock, a body, a key plug rotatable therein, key controlled locking tumblers in said body and plug, a plug locking means in said body on one side or" the locking tumblers therein, means for projecting said blocking means into the end of a tumbler bore in the plug to block rotation of the latter in one direction, said blocking means being disengageable from its blocking `position by a reverse rotation of said plug, and a corresponding blocking means in said body on the opposite side of the locking tumblers therein.

3. In a pin tumbler lock, a body, a key plug rotatable therein, key controlled locking tumblers in said body and plug, a plug blocking means in said body on one side of the locking tumblers therein, means for projecting said blocking means into the end of a tumbler bore in the plug t0 block rotation of the latter in one direction, said blocking means being disengageable from its blocking position by a reverse rotation of said plug, said blocking means comprising a plunger mounted to enter said tumbler bore in the plug at an abrupt angle thereto.

Ll. In a pin tumbler lock, a body, a Vkey plug rotatable therein, complementary bores in said plug and body with key controlled locking tumblers therein, the bore in the body being radial to said plug, two other bores in said body Y on opposite sides of the said tumbler bore, said other bores being substantially tangential to the plug and each positioned to be intersected by a locking tumbler bore in the plug when the latter is turned away from its normal locked position a limited distance, and a blocking plunger in each of said other bores with means for projecting the end and one side only of the same toward said plug and into an empty end of a locking tumbler bore.

5. In a pin tumbler lock, a body, a key Aplug rotatable therein, complementary bores in said plug and body with pin tumbler elements therein, the bore in the vbody being radial to said plug, two other bores in said bodyon opposite sides of the said .tumbler bore, said Yother bores being substantially tangential to the plug and each positioned to be intersected by a tumbler bore therein when said plug is turned away from its normal locked position, and a blocking plunger in each of said othei` bores with means for projecting the same toward said plug, each of vsaid plungers being respectively repressible by one edge oi a tumbler bore in the plug when the latter is turned back toward its normal locked position.

NORMAN B. HURD.

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